I use Lotus R5 and a Palm T3. But in terms of GtD implementation here is my folder setup

Standard Notes folders
Inbox
Drafts
etc etc

GtD Folders
-1 @Action
-2 @Waiting On
-3 Current Project Files
Seprate foler for each Project named exactly as per my Project List
-4 General Reference
-5 Completed Projects
Nothing fancy here I just use the Notes Folder Move option to move it from Current to Complete when its done.

For longer term archiving I am checking out the Notes Export facility and I am considering exporting all the emails to do with a completed project as structured text onto the fileserver along with the other project documentation prior to archiving. This will free up Notes server space and keep it manageable in the in the long term.

If you are looking for a product to sync your Treo and Lotus Notes I cant speak highly enough of mNotes at http://www.commontime.com. One thing you will find is that most syncing tools dont allow you to sync anything other than your inbox which makes no sense if you are trying to keep your data on current project with you.

The support team at Commontime is just brilliant. I'd send them an e-mail about syncing with your Treo before you download the trial version.

I've been collecting my thoughts today in order to respond to your question. I do not get to post to this forum as often as I would like; however, your question pushed my hot button on three topics that I am passionate about. (GTD, Notes, and Wireless)

For longer term archiving I am checking out the Notes Export facility and I am considering exporting all the emails to do with a completed project as structured text onto the fileserver along with the other project documentation prior to archiving. This will free up Notes server space and keep it manageable in the in the long term

w_i_t_n_a (great screen name, by the way ), why not just set up an archive database in Notes. It's automatic, and you can set the expiry period for the documents to be moved to the archive. This way you won't lose the Rich Text formatting and embedded objects, links etc. Best of all, there is nothing for you to buy. You already have the software! Should you ever need to restore messages from your live archive, you can simply move them back into your email database, or any other database for that matter.